Part Number: BDW53
Function: 45V, 4A, NPN Silicon Power Darlington Transistor
Package: TO-220 Type
Manufacturer: Bourns, Inc
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Description
The BDW53 is a 45V, 4A NPN Darlington power transistor designed for high-current switching and amplification applications, typically available in a TO-220 package. It features high current gain, strong thermal performance, and compatibility with complementary PNP devices in the BDW54 series. This device is commonly used in motor control, power regulators, and audio amplifier output stages.
Features
- High current gain with minimum hFE of 750 at IC=1.5A
- Power dissipation up to 40W at TC=25°C
- Designed for complementary pairing with BDW54 series
- Integrated Darlington configuration for high amplification
Pinout
Absolute Maximum Ratings (Tc = 25 °C)
| Parameter | Symbol | Value | Unit |
| Collector-Base Voltage | VCBO | 45 | V |
| Collector-Emitter Voltage | VCEO | 45 | V |
| Emitter-Base Voltage | VEBO | 5 | V |
| Collector Current | IC | 4 | A |
| Total Power Dissipation | Ptot | 40 | W |
| Junction Temperature | Tj | 150 | °C |
| Storage Temperature | Tstg | -55 to 150 | °C |
Design Notes
- Due to Darlington configuration, expect higher VCE(sat) compared to single BJTs
- Ensure proper heat sinking to maintain junction temperature within safe limits
- Base drive requirements are lower due to high current gain but must be controlled to avoid overdrive
- Consider switching speed limitations inherent to Darlington pairs
- Include flyback diodes when driving inductive loads
Typical Circuit Usage
- Low-side switching for motors and relays
- Linear voltage regulator pass transistor stage
- Audio amplifier output stage (class B or AB)
- LED strip or high-current load drivers
- Power control circuits with microcontroller interface
How to Choose This Part
- Select when high current gain is required with minimal base drive
- Suitable for applications below 45V and up to 4A load current
- Prefer when thermal dissipation can be managed effectively
- Use when complementary pairing with BDW54 is needed
- Not ideal for high-speed switching applications due to slower response
Applications
- Motor drivers and actuator control
- Power supply regulation circuits
- Audio amplification systems
- Industrial control systems
- Lighting control and LED drivers
Alternative / Equivalent Products
- BDW54 (PNP complementary pair)
- TIP122 (NPN Darlington transistor)
- TIP120 (lower voltage alternative)
- MJE800 series (power transistor alternatives)
- 2N6284 (similar Darlington transistor)
Other data sheets are available within the file: BDW53A, BDW53B, BDW53C, BDW53D
BDW53 Datasheet PDF Download
